Overview
EN ISO 15749-4:2004 - Ships and marine technology - Drainage systems on ships and marine structures - Part 4: Sanitary drainage, sewage disposal pipes - specifies design principles for sewage disposal pipes as part of sanitary drainage on ships and marine structures. It focuses on routing, pipework, disposal methods (storage-unit based and direct overboard), and required closing devices. For overall planning and basic system design see ISO 15749-1:2004.
Key topics and technical requirements
- Scope and context
- Applies to design of sewage disposal pipes within ship and marine-structure sanitary drainage systems.
- Integrates with other parts of ISO 15749 (Parts 1–5).
- Disposal methods
- Distinguishes disposal via storage units (collector tanks, sewage treatment plants, vacuum units) and direct overboard discharge by gravity.
- Disposal piping from storage units is treated as pressure lines.
- Closing devices and valves
- Closing devices (fittings) required in the disposal section between pump and wastewater outlet; must be certified by classification societies.
- Screw-down non-return valves at the shell; if valve cannot be placed at shell, connecting pipe must be thick-walled.
- Additional non-return fittings or pipe loops are required depending on ship list and position of inner openings (e.g., a 200 mm minimum crest/clearance and considerations for a 5° list are specified).
- Passenger ships have stricter requirements (additional shutoff non-return valves, gate valves when drains lie below bulkhead decks).
- Bypass and gravity piping
- Bypass lines permitted where discharge to sea is allowed; bypass must include shutoff and secondary closing devices and feed as close as possible to shell closing devices.
- Gravity drain piping closing devices must meet minimum requirements set out in Clause 5.
- Pipework and materials
- References to standard tube specifications (e.g., ISO 4200, ISO 9329-1, ISO 9330-1) for material/dimension guidance.
- Type N steel pipes are indicated as sufficient for disposal piping in specified areas.
- Wastewater discharge connections
- Discharge connections intended for shore reception must include a flange compatible with the international wastewater shore connection (MARPOL flange).
Applications and who uses it
- Practical for naval architects, shipbuilders, marine engineers, ship operators, classification societies, and shipyard piping designers.
- Used when designing or certifying sanitary drainage, sewage disposal systems, discharge points, and pipe routing for passenger ships, cargo vessels, cruise ships, and offshore marine structures.
- Supports compliance with MARPOL-related shore reception requirements and classification rules for closing devices.
Related standards
Keywords: EN ISO 15749-4:2004, sanitary drainage, sewage disposal pipes, ships, marine structures, MARPOL flange, drainage systems, non-return valve, wastewater discharge, pipework design.
